Hash .scm/.img/.bin files while dumping CD

[JohnVeness]

Similar to #108, which has greatly increased the speed of dumping DVDs, can you do similar for when dumping CDs?

I'm not sure exactly how much of this is code within your control, but I'm thinking that at the very least you could hash the .scm file while you're reading from the physical CD, and hopefully you could also hash the .img file while you're converting the .scm, and could hash the .bin file(s) while converting the .img.

[malvarenga123]

I think the time/performance gain would be negligible for CDs. Most of the time is spent unscrambling the .scm file, which doesn't happen for DVDs/BDs.

[JohnVeness]

For me, the hashing takes about a minute, out of approx ten minutes for the dumping and all the other processing (ignoring protection scanning). So I'm guessing hashing on the fly would save at least a few percent of time. Not a lot, but might be worth it.